In response to external and internal signals, mammalian cells elicit post-transcriptional changes in gene expression patterns that govern the global cellular response. We are keenly interested in the mechanisms that regulate the expression of proliferative, cell cycle-regulatory, and stress-response proteins. Over the past 22 years, this Project has examined numerous RBPs, noncoding (nc)RNAs, and their influence on gene expression patterns. We have paid particular attention to their impact on the stress and proliferative response of cells, two processes that are severely impaired during aging. In the past funding period, we have continued to focus on RBPs implicated in the cellular response to mitogens and stresses, but have expanded substantially into ncRNAs linear long noncoding RNAs (lnc)RNAs and circular (circRNAs) that influence these responses. Since impaired adaptation to mitogens and cell injury underlie various cancer traits (cell proliferation and survival, angiogenesis, invasion, metastasis, and evasion of immune recognition), many studies in this project use cancer cells as the model system. We have continued to investigate the influence of RBPs and ncRNAs on the homeostasis of the intestinal epithelium, cancer cells, and immune cells. During this review period, many of these studies have been carried HuR in collaboration with other groups, including those led by Drs. J.-Y. Wang (Xiao et al., Americal Journal of Physiology - Cell Physiology, 2019; Xiao et al., Gastroenterology, 2019), K. Prasanth (Sun et al., Nucleic Acids Research, 2018), and A.C. Panda (Pandey et al., Methods, 2018; Das et al., Aging News and Views, 2018; Das et al., International Journal of Medical Sciences, 2019). We also reported on noncoding RNAs influencing hepatocellular carcinoma and Kaposi sarcoma (Noh and Gorospe, Hepatology, 2018; Tsitsipatis and Gorospe, Annals of Translational Medicine, 2019). Over the past 12 months, we have also reported on ncRNAs involved in cancer, proliferation, stress-response, senescence, and other processes relevant to aging. We have continued to create tools to investigate circular RNAs and other noncoding RNAs (Panda and Gorospe, Noncoding RNA Investigation, 2018; George et al., Open Biology, 2018; Pandey et al., WIRES RNA, 2019).